diff --git a/sk1/compressor.h b/sk1/compressor.h
index e69de29..6f7f641 100644
--- a/sk1/compressor.h
+++ b/sk1/compressor.h
@@ -0,0 +1,5 @@
+#include <stdio.h>
+int compress_1(const char *a, const char *b);
+int compress_2(const char *a, const char *b);
+int decompress_1(const char *a, const char *b);
+int decompress_2(const char *a, const char *b);